The invention relates to blast and ballistic shielding for structural support elements for buildings, bridges, transportation infrastructure and vehicles, and in particular to pre-formed shielding which provides protection from the effects of blast(s) from explosives or accidental or malicious destruction.
Due to increased threats and awareness of potential terrorist activities, increased attention is being given to protecting structures of all types against damage from fire, explosion, and other threats, malicious and accidental, to structural elements of buildings and the like. An example is U.S. Pat. No. 6,960,388 to Hallissy, et al. which discloses and claims flexible but intumescent coatings for an electrical conduit which, when exposed to intense heat, forms an expandable insulative layer about the conduit. This provides increased protection for electrical and communication cables and wires which the conduit encases.
There is a need for blast and/or ballistic impact resistant barrier structures for use in both existing and new construction/manufacturing for exposed structural elements. Exposed structural elements of buildings and transportation infrastructure are particularly vulnerable targets for terrorist activity. One particularly vulnerable structural element that is widely used in construction is tension cables. Tension cables, generally of steel, have long been used in design and construction of suspension bridges, and are finding increasing use in structures of all types. While designs employing such tension cables always employ a certain degree of redundancy, damages to numerous cables can have a catastrophic effect. Damage in the case of explosive devices is particularly problematic, since even small “nicks” in highly tension metal can create failure modes which are largely absent in non-tension structures.
It would be desirable to provide systems that are relatively inexpensive and have an acceptable weight efficiency which can protect both existing and new exposed structural elements against damage by explosive devices, both in terms of the energy created by the explosion per se as well as from flying objects/debris created during explosive blasts, as well as from other threats to the integrity of the structural element.